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Inspect the NetBIOS name cache with nbtstat on Windows

The forgotten legacy tool that still answers 'which Windows machine is \OLDFILESERVER?' and resolves names on networks without DNS.

WindowsnetworknetbiostroubleshootingLow risk
Run `nbtstat -c` to list cached NetBIOS name-to-IP mappings, or `nbtstat -A <ip>` to query a machine's names directly.

01Command

Command
$ nbtstat -c

02What it does

Legacy Windows shares, printers, and old NAS devices still register NetBIOS names, and when DNS fails on a LAN these names are what SMB falls back to. `nbtstat -c` shows your local cache, `nbtstat -A <ip>` asks a specific machine what names it owns (its response includes its MAC address), and `nbtstat -R` purges the cache so stale names reload. It's read-only unless you use -R or -RR, so it's safe to poke around with.

03Risk

RiskLow risk

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

  • NBTSTAT - Windows CMD
    SS64 · technical · 2026-09-17
    Evidence: SS64 explains nbtstat -c displays cached NetBIOS names and -R reloads the cache from the LMHOSTS file.
  • nbtstat | Microsoft Learn
    Microsoft · vendor-doc · 2026-09-17
    Evidence: Microsoft documents nbtstat switches: -c lists the NetBIOS name cache, -A queries a remote machine by IP address, -R purges the cache.

Last verified: 2026-09-17 · Category: Network

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